There is a great demand for fire retardant fibers. Cotton and rayon fibers, fabrics and garments probably compose the most flammable textile materials in use today. Many of the synthetic fibers as well as fibers of animal origin are less flammable but the problem of imparting fire retardancy thereto still exists.
It is generally accepted that the earliest attempts to reduce the flammability of cellulose textiles was made by Wilde in 1753 in England and later by Gay-Lussac in France in 1821. Their studies revealed the utility of various inorganic salts as fire retardant agents for cellulose. The development of semi-durable and durable fire retardant finishes began in the early 1900s but it was not until the 1950s that truly durable finishes, i.e., resistant to ordinary laundering, were available. The very early finishes were based on the precipitation of metal oxides within the fiber. Later developments included the discovery that combinations of certain halogenated compounds and antimony oxide formed an efficient and moderately durable fire retardant for cellulose.
We have now discovered a group of halogenated compounds which can impart an effective degree of flame retardance to synthetic fibers and solid polymers. In U.S. Pat. No. 3,644,493, there is described 2,3-dihaloalkyl compounds as flame retardant for various natural and synthetic fibers. All of these compounds are esters of allyl alcohol, which are then halogenated in contrast to the present compounds which are derivatives of allyl and diallyl amines and are, in fact, halogenated amides.
Accordingly, it is the object of this invention to provide a new group of compounds for the imparting of flame resistance to synthetic fibers. This and other objects of the invention will become apparent from the following detailed description of the invention.